Heating stove



Oct. 6, 1931. H. JUNKERS HEATING STOVE Filed Sept. 3, 1926 //7 van for Patented Oct. 6, 1931 UNI-TED STATES PAT m omen nuao nmxans, or nnssau, ennmmz nmrme srovn Application filed September 3, 1928, Serial No; 183,492, and in Germanynugult 8, i925.

My invention refers to heating stoves more especially of the kind in which a tubular or other shell traversed by hot gases is surrounded by an outer shell spaced from it. It has special reference to heating stoves as described and claimed in my patent of the United States No. 1,614,439.' In the stoves disclosed in this copending application the heat was emitted by radiation from an inner to an outer shell, the space between the two shells being closed at least on one side and the distance between the two shells diminishing from the entrance to the exhaust end of the inner shell in order to obtain a uniform surface temperature cp the outer shell. This means of equalizin and keeping low the temperature of the surface of the outer shell involves a more or less conical form ofaone or both shells. According to the present invention now I have found that I can obtain the desired equalization of the temperature of'the sur-' face of the outer shell also by other means, which are preferable both from a technical and from an economical point ofview.

According to the present invention I provide means associated; with one or both of said shells, which secure a transmission of heat from the inner to the outer shell resulting in a substantially uniform surface temperature throughout the length of the outer shell.

I have found it particularly advantageous to employ an inner shell bent upon itself so as to be composed of an ascending and a descending branch, the current of hot gases "being thus compelled to first flow in onefandthen in the opposite direction. An arrangement of this kindhas the effect that the ascending branch having the higher tem-. perature and the descending branch having v the lower temperature will cooperate in' formingat all points a substantially uniform average temperature, so that a uniform transmission of heat is obtained throughout the height of the stove and the surface temperaturesof the .outer shell are substantially uniform and comparatively low. I can further increase this effect by providing for a conductive connection in one ormore points of the ascendin and descending branches of the-inner she I, so that the he'at across these connections will flow of act towards further improvin the equalizing of temperature. Prefera lythe crosssectional area of the U-shaped inner shell is enlarged in the ascending branch and diminishes towards the exhaust end, so that with the increasing height of the stove an increase in .the heatin surface is obtained which also acts towar s keeping the quantity of heat transmitted by radiation and in consequence thereof also the surface temperature of the outer shell substantially equal in all places.

I have further found that it is possible to keep the surface temperature of the outer shell low, particular] near the entrance end of the heating gases y arranging the inner shell or the combustion chamber forming part thereof in inclined position in such manner that the transmission of heat by radiation from the hottest part will act on a greater part of the surface of the outer shell and will only gradually take place on the shortest way.

In all the arrangements a transmission of I have found that the application of the I present invention to radiator stoves being a combination of a plurality of heating elements offers particularadvantages for the reason that the meansfor obtaining a uniformity of the surface temperature render it possible to-arrang'e the inner and outer shells close together, whereb thinner heating elements are obtained, t e combination as heating elements, in which of which results in a stove requiring less room. If the means disclosed above are distributed over the circumference of the shells it is possible to obtain a very uniform surface tern erature also with flat or "elliptic heating e ements, inasmuch as such elements allow utilizing the space available particularly easily, while on the contrary the obtention of a uniform and comparativel low temperature with heating elements 0 this kind as hitherto used proved particularly dificult. If radiators of this kind are used the ath of the hot gases is reversed, I obtain the urther advantage that the entrance and exhaust ends of the hot gases are arranged close together and in a low position, so that the exhaust gas collecting conduits hitherto arranged at the upper ends of the heating elements can be dispensed with and the heating surfaces are therefore readily accessible from everywhere and can easil be cleaned.

In the drawings a xed to this specification and forming part thereof several forms of an oven embodying my invention are illustrated diagrammatically by way of example.

In the drawings Figs. 1 and 2 are a vertical and cross section, respectively, of one form of a stove according to my invention.

Fi 3 is a vertical section of a stove having t e inner gas-heated shell connected to intermediate heating conduits.

Fig. 4 is a similar view of a stove pro-- vided with means for efiecting an aUtOIHSLtIG circulation of the air enclosed between the two shells, and

V Fig. 5 is a vertical section of a stove in whic the heat radiation surfaces of the outer shell are enlarged by ribs.

Referring first to Figs. 1 and 2, 2 is the inner shell in direct contact with the hot gases and "3 is the outer shell, which is s aced from but connected with the inner s ell both at the top and at the bottom in a gas-tight manner and is heated mainly py radiation.

- e inner shell 2 is bent upon itself, having substantially U-shap'e, and the hot gases entering at the bottom are thusforced to flow first in upward and thereafter in downward direction. In order to secure a uniform radiation of heat from the inner to the outer shell the two branches of the inner shell areconnected either in some places or all over their length by heatconductive members 9, and in consequence of this arrangement the equalization of temperature already occurs at the inner shell itself. In order to prevent the outer shell from over-heated near the entrance end-o the. ot ases, this part of the inner shell is preferab ylinclined in such manner that, as shown by t e arrows in Fig. 9, the transmission of heat by radiagases tion from the hottest parts of theinner shell larly adapted for the heating 0 large rooms. In this stove the hot ascend in an inner shell 2a surrounde at its bottom and by an annular conduit 12 which is connected with the top portion of the inner shell by branch conduits 212. From the am nular conduit 12 the gases can escape across the intervening space and across the wall of the outer shells 3.

Fig. 4 shows means whereby a permanent automatic circulation of the air enclosed between the two shells is obtained. In Fig. 4 a heat radiating tube 13 is inserted in the inner shell in such manner that a bend is formed between two substantially parallel parts of this shell.

In the oven illustrated in Fi 5 the heat radiating surfaces are enlarge by the arrangement of ribs 8 in those arts of the outer shell 3 which are arranged at a greater distance from the inner shell 2.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for obvious modifications will occur to a person skilled in the art.

1. Heating stove comprising an inner shell arranged to be traversed by hot gases, an outer shell spaced from and surrounding said inner shell, the space enclosed between the two shells being secured against the entrance of air and of the hot gases traversing said inner shell, and means associated with one of said shells for securing a'trans mission of heat from the inner to the outer shell resulting in a substantially uniform surface temperature throughout the length of said outer shell.

2. Heating stove comprising an inner shell bent upon itself and arranged to be traversed by hot gases, an outer shell s aced from and surrounding said inner she the space'enclosed between the two shells being secured against the entrance of air and of the hot gases traversing said inner shell and means associated with one of said shells for securing a transmission of heatfrom the inner to the outer shell resulting in a substantially uniform surface temperature throughout the length of said outer shell.

3. eating stove comprising an inner shell bent upon itself and arranged to be then decreasing from the entrance to the 125 exhaust end, an outer shell aced from and surrounding said inner she the space enclosed between the two shells bein secured against the entrance of air and o the, hot traversing said inner shell and means associated with one of said shells for securing a'transmission of heat from the inner to-the outer shell resulting in a substantially uniform surface temperature throughout the length of said outer shell.

4. Heating stove comprisingan inner shell bent upon itself and arranged to be traversed by hot gases, an outer shell 5 aced from and surrounding said inner shel the space enclosed between the two shells being secured against the entrance of air and of the hot ases traversing said inner shell, a heat-con uctive connection between said shells and means associated with one of said shells for securing a transmission of heat from the inner to the outer shell resulting.

in a substantially uniform surface temperature throughout the length of said outer shell.

5. Heating stove comprising two concentric shells spaced from one another and connected in a gas-tight manner so as to form a closed space between them, the space enclosed between the two shells being secured against the entrance of air and of the hot gases traversin said inner shell, and a gas conduit exten g from the inner shell across said space and through said outer shell.

6. Heating stove comprising an inner shell arranged to be traversed by hot gases,

an outershell spaced from and surrounding said inner shell,'the space enclosed between the two shells bein secured against theen trance of air and o the hot gases traversin said inner shell and means associated wit the entrance end of said inner shell for reducing radiation of heat towards said outer shell.

7. Heating stove comprising an inner shell arranged to be traversed by hot gases said inner shell being formed with a hen between two substantially arallel parts, and an outer shell spaced rom and sur rounding said inner shell, said shells being connected in a gas-tight manner, the space enclosed between thetwo shells bein secured against the entrance of air and o the hot gases traversing said inner shell.

In testimony whereof I aflix my signature.

HUGO JUNKERS. 

